Biochemical characterization of cone cyclic nucleotide-gated (CNG) channel using the infrared fluorescence detection system

Adv Exp Med Biol. 2012:723:769-75. doi: 10.1007/978-1-4614-0631-0_98.

Abstract

Cone vision mediated by photoreceptor cyclic nucleotide-gated (CNG) channel is essential for central and color vision and visual acuity. Cone CNG channel is composed of two structurally related subunit types, CNGA3 and CNGB3. Naturally occurring mutations in cone CNG channel are associated with a variety of cone diseases including achromatopsia, progressive cone dystrophy, and some maculopathies. Nevertheless, our understanding of the structure of cone CNG channel is quite limited. This is, in part, due to the challenge of studying cones in a rod-dominant mammalian retina. We have demonstrated a robust expression of cone CNG channel and lack of rod CNG channel in the cone-dominant Nrl−/− retina and shown that the Nrl−/− mouse line is a valuable model to study cone CNG channel. This work examined the complex structure of cone CNG channel using infrared fluorescence Western detection combined with chemical cross-linking and blue native-PAGE. Our results suggest that the native cone CNG channel is a heterotetrameric complex likely at a stoichiometry of three CNGA3 and one CNGB3.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Basic-Leucine Zipper Transcription Factors / genetics
  • Blotting, Western / methods*
  • Color Vision Defects / metabolism*
  • Cyclic Nucleotide-Gated Cation Channels / analysis
  • Cyclic Nucleotide-Gated Cation Channels / chemistry
  • Cyclic Nucleotide-Gated Cation Channels / metabolism*
  • Electrophoresis, Polyacrylamide Gel
  • Eye Proteins / genetics
  • Fluorescence
  • Infrared Rays*
  • Mice
  • Mice, Mutant Strains
  • Protein Structure, Quaternary
  • Retinal Cone Photoreceptor Cells / metabolism*

Substances

  • Basic-Leucine Zipper Transcription Factors
  • CNGB3 protein, mouse
  • Cnga3 protein, mouse
  • Cyclic Nucleotide-Gated Cation Channels
  • Eye Proteins
  • Nrl protein, mouse